1. Field of the invention:
This invention relates to an improved fixing unit that is used for an image formation apparatus such as an electrophotographic copying machine, etc.
2. Description of the prior art:
In general, fixing units used for image formation apparatuses have a pair of rollers, one of which is an upper roller and the other of which is a lower roller. An upper housing containing the upper roller and a lower housing containing the lower roller are designed so that both housings can be rotated and opened and closed around a shaft, which is parallel to the pair of rollers. Conventionally, this lower housing is fixed by screws in a set position inside of the body of the image formation apparatus to thereby hold the fixing unit at a fixed place in the image formation apparatus. However, at times of inspection and so on, the fixing unit is taken out of the body of the image formation apparatus, and when it is again fixed into the body, even a small displacement in its position causes such problems as paper jams, arising from unsatisfactory operation of the fixing unit. In addition, placement of the fixing unit into the body of the image formation apparatus and removal of it as well are carried out from the front of the body of the apparatus, so that special coupling devices and sliding rails may be necessary. This makes the structure of both the body of the apparatus and the fixing unit, more complex and makes the miniaturization of the image formation apparatus and the fixing unit difficult.
On the other hand, in the space of the upper and lower rollers, the paper having an image thereon that enters may wrinkle, depending on the kind of paper used, which sometimes leads to failure in the step of fixation of the image. This is because a device to feed the paper between the rollers at the most appropriate angle has not yet been developed, notwithstanding the face that the most appropriate angle at which the paper should be introduced between the rollers depends on the kind of paper.